1. MA Jones, PT, MS, ATP, is a clinical physical therapist and doctoral student, College of Allied Health, Department of Rehabilitation Science, University of Oklahoma Health Sciences Center, 1600 N Phillips, Oklahoma City, OK 73104 (USA).
2. IR McEwen, PT, PhD, is Presbyterian Health Foundation Presidential Professor and Vice Chairman, Department of Rehabilitation Science, University of Oklahoma Health Sciences Center
3. L Hansen, PT, MS, is a clinical physical therapist and doctoral student, College of Allied Health, Department of Rehabilitation Science, University of Oklahoma Health Sciences Center